Valve means



Jan. 20, 1959' J. DOLZA 2,869,526

VALVE MEANS Filed June 29, 1956 I 2 Sheets-Sheet 1 /0 COA/TQUL umr b\ 4 25 IN VEN TOR.

J5 za $66M ATTORNEY Jan. 20, 1959 J. DOLZA ,5

VALVE MEANS Filed June 29,-1956 2 Sheets-Sheet 2 INVE TOR (/55?! 0/20 ATTORNEY United States Patent VALVE MEANS John Dolza, Fenton, Mich., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application June 29, 1956, Serial No. 594,730

6 Claims. (Cl. 123-119) The present invention relates to a pressure sampling valve for sequentially sampling a plurality of individual pressures to produce a resultant signal proportional thereto and more particularly to a sampling valve adapted to sequentially sample the individual amounts of air entering the cylinders of an internal combustion engine and to transmit a resultant signal proportional thereto to a fuel control for the engine.

In certain instances it is desirable to obtain a signal that accurately represents the total flow of a fluid that is divided into several individual flows even though it is impossible to directly measure the total flow. For example, in a multicylinder, internal combustion engine where the fuel is injected into the charges adjacent the cylinders, the induction system may include a plenum chamber and a plurality of individual intake passages or ram pipes that interconnect the chamber with the cylinders. If these intake passages or ram pipes are tuned to produce surges of air in the passages at one or more engine operating conditions. the surges of air in the ram pipes will tend to dynamically supercharge the cylinders and thereby materially increase the volumetric efficiency of the engine. It will thus be seen that the volumetric efficiency of the engine will not be a straight line function and, moreover, the pressure in the plenum chamber which will not reflect the resonant surges will not be accurately indicative of the air flow. Thus it has been found that the fuel control portion of the fuel injection system cannot be satisfactorily actuated by a pressure obtained from outside of the ram pipes, i. e., inside of the plenum chamber. Accordingly, since engine volumetric efficiency is not proportional to air density immediately past the throttle valve or in the plenum chamber, but instead to air density in the vicinity of the intake valves and toward the end of the charging cycle, it is desirable to obtain the air pressure signal from the vicinity of the intake valve only during the period when the pressure is representative of actual air density.

Accordingly, it is proposed to provide a rotary air pressure sampling valve which will sequentially interconnect the interior of each of the ram pipes with a centralized pressure chamber which, in turn, is interconnected with a pressure responsive control unit in the fuel injection system. This valve will include a rotary disc that is driven at camshaft speed and has an aperture there through which will register with the ends of sampling tubes and open them to the pressure chamber. The sequence of sampling will be the same as the firing of the cylinders and thus will occur during corresponding portions of the resonant surges. The timing of this sampling will occur during a portion of the cycle where the air pressure will represent the density of the charge. Thus the fuel will be accurately metered as a direct function of the quantity of the total air flow in the individual ram pipes.

Figure 1 is a diagrammatic view of an internal combustion engine and fuel control therefor with a pressure sampling valve therein shown in cross section.

source to said nozzles in proportion to said air flow.

Figure 2 is a transverse cross-sectional view of an internal combustion engine incorporating the present invention.

Figure 3 is a cross sectional view taken substantially along the plane of line 3-3 in Figure 1.

Figure 4 is a cross-sectional view taken substantially along the plane of line 44 in Figure 1.

Referring to the drawings in more detail the present invention may be incorporated in a fuel injection system 10 adapted for use on a so-called V-type, internal combustion engine 12 having a cylinder block 14 with a pair of angularly disposed banks 16 of cylinders. The engine induction system 18 includes an enlarged plenum ch mber 20 having a throttle valve inlet 22 and a plurality of intake passages or ram pipes 24 that interconnect the plenum chamber 20 with the various cylinders. These ram pipes 24 are preferably constructed so that they are tuned to resonate at one or more engine operating conditions. Thus during such conditions there will be surges of air flowing in the ram pipes 24 that will tend to dynamically supercharge the cylinders. Normally, these surges of air will be reflected back down the pipe 24 from ice the open end thereof without being apparent in the air in the plenum chamber 20.

The ch rge for the various cylinders may be formed by injecting the fuel into the air by means of the fuel injection system 10. This system 10 include separate injector nozzles 26 directed into the induction passages 24 for injecting metered quantities'of fuel immediately adjacent the intake valves. The quantity of injected fuel is metered by a control unit 28 interconnected with a source of fuel under pressure and responsive to an air pressure signal indicative of the quantity of air flow into the engine 12 so as to meter the flow of fuel from said The pressure signal for the control unit 28 may be obtained by means of a sampling valve 30 which is adapted to be driven in timed relation with the engine 12. The valve 30 is effective to sequentially sample the pressures in the ram pipes 24 and combine the samples to produce the resultant signal.

The present valve 30 includes a cylindrical housing 32 and a base portion 34 which have mating flanges 36, 38 thereon that are secured to each other by bolts. These flanges 36. 38 are also adapted to form a mounting for the valve 30. Although the valve may be placed at any suitable location, it has been found preferable for the valve 30 to be mounted on a web extending between the banks 16 of cylinders so that it may be conveniently driven from the engine camshaft.

The base 34 includes an axial passage that has an upper portion 40 of enlarged diameter and a lower portion 42 of reduced diameter. A stub shaft 44 may be mounted in this passage so that the enlarged hub 46 will rotate on a bearing member 48 at the bottom of the enlarged portion 40. A gear 50 on the bottom of the stub shaft 44 may mesh with a gear on the camshaft or any other suitable means for driving the valve 30 in timed relation to the engine 12. The enlarged hub 46 may also include a downwardly directed axial passage 52.

The cylindrical housing 32 may also include an axial passage having an enlarged upper end 54, an intermediate center portion 56 and a reduced lower portion 58 that corresponds to the passage 52 in the hub 46. These portions may be separated from each other by shoulders 60, 62 having horizontal surfaces. In addition, the housing 32 may include a series of circumferentially spaced parallel passages 64. These passages are drilled to form a series of sampling chambers 66 spaced about the lower portion 58 of the passage to form openings in the lower shoulder 62. Each of these sampling chambers 66 may be interconnected with the individual ram pipes 24 adjacent their inner ends by a series of sampling tubes 68. These chambers 66 are preferably interconnected with the ram pipes 24 in the same sequence as the firing order of the cylinders. In other words if, for example, the ffiring order of the engine is l, 3, 6, 5, 4, 8, 7, -2,"the chamber 66 will be connected to the ram pipes 24 for the cylinders in the following order 1, 3, 6, 5, 4, 8, 7,

A rotor 78 may be disposed in the centersection 56 of the axial passage so as to be supported "by thelow er shoulder 62. An axial passage 72 may extend through the rotor 7:) so that it is positioned to register with the various chambers 65. A stator or disk plate 74 may be locked to the shoulder 62 by a pin '76 so that the slots 78 therein will register with the open ends of the chambers 66 and form a restricted opening therebetween. A floating shaft 86 may have the lower end seating on a transverse pin 82 in the axial passage 52 in the enlarged hub 4-6 while the upper end drivingly locks on a similar pin 84 in the rotor '70. It will thus be seen that the rotor 79 will rotate in sequence with the engine. provide a seal and reduce friction the rotor 79 is preferably of a self-lubricating material such as graphitar.

A hold-down plate 86 may ride on the top of the rotor 70 to bias it and the stator 74 against each other and the shoulder 62. A cavity in the hold-down plate 86 will form'a pressure tap chamber 90 in communication with the passage 72. 'The stationary cap 92 is bolted to the top of the housing 32 to form a seat for a spring 94 acting against hold-down plate 86 and also a race for the balls 96. A conduit 93 may be threaded into the cap 92 to interconnect the pressure tap chamber 90 with the control unit.

It may thus be seen that during operation of the engine the gearSd will drive the rotor 70 in timed relation with the engine 12. The passage 72 in the rotor 70 will then'sequentially register with the openings formed by parallel chambers 66 so as to successively interconnect these chambers 66 with the central pressure tap chamber 90 above the rotor 70. Thus the valve 30 will sample the individual air pressures in the ram pipes 24 and transmit a pressure signal proportional to the total of the pressures in the ram pipes 24 at the points of sensing to the control unit 28. By employing a stator plate 74 having the correctly shaped openings 78 therein, a restricted exit between the ram pipes 24 and the chamber it? may be pro vided which will control the characteristics of the resultant signal. It may be noted that the present openings '78 are radial slots having a limited circumferential width. By properly shaping the widths of the slots 78 and the phase of the rotor 70 with respect to the operation of the engine 12, it will be seen that the pressure samples may be obtained during any desired fragments of the engine cycle. It will thus be apparent that the resultant pressure signal transmitted to the fuel control unit 23 will reflect the maximum density in the ram pipes 24. As a result the fuel will be accurately metered in proportion to the air entering the engine 12.

It is to be understood that, although the invention has been described with specific reference to a particular embodiment thereof, it is not to be so limited since changes and alterations therein may be made which are within the full intended scope of this invention as defined by the appended claims.

I claim:

1. In an engine having a plurality of cylinders and intake passages for charging said cylinders and an injection system for injecting metered quantities of fuel intosaid passages, a sampling valve comprising a stationary housmg having a passage extending axially therethrough with portions of different diameters separated by a shoulder, a plurality of sampling chambers adapted to be interconnected with said intake passages and disposed around said axial passage, said chambers forming a series of circumferentially spaced openings ,in said shoulderia rotor having one side thereof supported by said shoulder and In order to being driven by said engine in timed relation to the operation thereof, a pressure chamber disposed on the other side of said rotor and being operatively interconnected with a control unit in said injection system, said rotor including a passage for intermittently interconnecting said sampling chambers with 'said pressure chamber to produce a resultant signal therein proportional to the flow through said intake passages and being effective to actuate said control unit in response thereto.

2. In a multicylinder engine having an induction system with a plurality of intake passages that communicate with the engine cylinders and that are adapted to resonate during one or more engine operating conditions, a fuel injection system comprising means for injecting fuel into said intake passages adjacent said cylinders, a control unit for metering the quantity of said injected fuel and a pressure sampling valve comprising a stationary member having a plurality of sampling chambers interconnected with said intake passages and a rotor adapted to be driven in timed relation to the operation of said engine for individually interconnecting said sampling chambers with a common pressure chamber operatively interconnected with said control unit so as to produce a resultant signal indicative of the individual flows'for actuating said unit in response thereto.

3. A fuel injection system for a multicylinder, internal combustion engine having separ'ateintzike passages for "said cylinders, said injection system comprising a plurality of injector nozzles communicating with said intake passages for injecting metered quantities of fuel into said passages, a control unit operatively interconnected with said injector nozzles and being effective to meter the quantity of injected fuel delivered thereto, a sampling valve adapted to intermittently "sense the individual air flow in said intake passages in 'timed relation with the operation of said engine and to transmit a resultant signal proportional thereto to said control unit. 7 4. A fuel injection system 'for a niulticylinder, internal combustion engine having separate intake passages for said cylinders, said injection system comprising-a plurality of injector nozzles communicating 'with said intake passages for injecting metered quantities of fuel into said intake passages, a control unit operatively interconnected with said injector nozzles and being effective to meter the quantity of the injected fuel delivered thereto, a sampling valve having a pressure chamber interconnected with said control unit and having a rotor driven in timed relation with the operation of said engine to intermittently interconnect said intake passages with said pressure chamber to form a resultant signal effective to actuate said unit in response thereto.

5. A fuel injection system for amulticylinder, internal combustion engine having separate intake passages for said cylinders, said injection system comprising a plurality of injector nozzles communicating'withfsaid intake passages for injecting metered quantities -off-fuel into said passages, a control unit'operativ'ely interconnected with said injector nozzles and being effective to meter the quantity of injected fuel delivered thereto, a sampling valve including a housing having an axial passage with a shoulder therein, a rotor having one side thereof supported by said shoulder, a pressure chamber on the opposite side of said rotor interconnected 'with said control unit and a passage through said rotor for sequentially interconnecting said pressure chamber with said intake passages so as to produce a resultant signal proportional thereto and effective to actuate said control unit.

6. In a multicylinder, internal combustion engine, the combination of an induction system having a plurality of intake passages for charging said cylinders, said passages being adapted to resonate during one or more engine operating conditions, a fuel injection system including an injector nozzle disposed in each of said intake passages for injecting metered quantities of fuel thereintoand a control unit operativ'ely interconnected with said injector the individual air pressures in said intake passages during some predetermined proportions of the cycle of flow signal proportional to the air flow through said passages effective to actuate said control unit.

through said intake passages and to produce a resultant References Cited in the file of this patent UNITED STATES PATENTS Stillwagon Mar. 2, 1943 Wilkening Sept. 21, 1948 Vanni June 23, 1953 

